The Justicar also gets a 10 square burst AE that only targets enemies.
10. That's most of the battlefield. And it does half damage even on a miss
The Stormwarden gets to hit, what? Everyone adjacent to him at best? Pfffft. And he has to give up his ability to use a shield to do that too. His utility ability isn't even that great. He can drop his defenses to hit a bit more often. Which would be fine if he was ranged but seems suicidal for a meleer. A meleer that needs to be surrounded to deal the most damage at that.
I think I'll take the ability to wear plate-mail, use a shield and still nuke most of the battlefield, thanks.
Just let them play as they will. The problem will sort itself out.